Re: [PATCH] boot: image-fdt: downgrade -EINVAL reservation failure to debug

[Emanuele Ghidoli <ghidoliemanuele@gmail.com>]

On 7/13/26 10:45, Joseph Guo wrote:
> When boot_fdt_handle_region() attempts to reserve a DTS reserved-memory
> region via lmb_alloc_mem(), it may receive -EINVAL if the region's
> physical address falls outside the LMB-managed memory range (i.e.
> below PHYS_SDRAM on platforms where U-Boot does not manage the lower
> DRAM window).
> 
> A typical example is platforms like i.MX95 where PHYS_SDRAM starts at
> 0x90000000, but remoteproc/rpmsg carveouts (vdev vrings, vdev buffer,
> resource table) are placed at 0x88xxxxxx by hardware convention. Those
> addresses are unreachable by U-Boot's allocator anyway, so failing to
> mark them reserved has no practical consequence -- U-Boot will never
> accidentally place the initrd or FDT blob there.
> 
> Printing ERROR for a condition that is harmless and expected on many
> platforms is misleading. Downgrade the -EINVAL case to debug() to
> suppress the spurious output while preserving full visibility under
> DEBUG/log builds.
> 
> Real failures (e.g. -EEXIST from an overlapping reservation) continue
> to be reported as ERROR.
> 
> Fixes: 623f6c5b6ab7 ("boot: image-fdt: free old dtb reservations")
> Signed-off-by: Joseph Guo <qijian.guo@nxp.com>
> ---
>  boot/image-fdt.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/boot/image-fdt.c b/boot/image-fdt.c
> index 9e0e0f93edd34ae9056926883b1a802858e179d9..2175fa338f55110862100fa9f491a0957e85ce56 100644
> --- a/boot/image-fdt.c
> +++ b/boot/image-fdt.c
> @@ -95,6 +95,9 @@ static void boot_fdt_handle_region(u64 addr, u64 size, u32 flags, bool free)
>  		debug("   %s fdt memory region: addr=%llx size=%llx flags=%x\n",
>  		      free ? "freed" : "reserved", (unsigned long long)addr,
>  		      (unsigned long long)size, flags);
> +	} else if (ret == -EINVAL) {
> +		debug("   skipping fdt memory region outside LMB range (addr=%llx size=%llx flags=%x)\n",
> +		      (unsigned long long)addr, (unsigned long long)size, flags);
>  	} else {
>  		printf("ERROR: %s fdt memory region failed (addr=%llx size=%llx flags=%x): %ld\n",
>  		       free ? "freeing" : "reserving", (unsigned long long)addr,
> 
> ---
> base-commit: 6741b0dfb41dc82a284ab1cff4c58af6ef2f3f9c
> change-id: 20260713-downgrade-f8319ab2d75b
> 
> Best regards,

Hi Joseph,

Tested on Toradex Aquila iMX95, which has reserved-memory regions for
the Cortex-M7 (vrings, vdev buffer, resource table) below PHYS_SDRAM.
The spurious ERROR messages are gone and boot is unaffected.

Kind regards,
Emanuele

Tested-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>